// package com.rit; public class JavaLecture5 { public static void main(String[] args) { // System.out.println("Hi Java"); // Simplest "Procedural-style Programming" program should have at least one "class" // and the "main method" inside it to start the program. // The "main method" is the entry point for any applications. // public class JavaLecture5 // Here is a class named "JavaLecture5". The class contains the "main method" for starting the program. // - "public" keyword is an access modifier // - "class" keyword is used to declare a class in java // public static void main(String[] args) // - The keyword "public" indicates that the method can be invoked from everywhere // - The keyword "static" indicates the method can be invoked without creating an instance of the class // - The keyword "void" indicates the method doesn't "return" any value // - The array variable "args" contains arguments entered at the "command line" if there are no arguments then the array is empty // Java Variables // DataType variableName = value; String msg; msg = "Hi Java"; System.out.println(msg); int count = 5; System.out.println(count); boolean status = true; status = false; System.out.println(status); double x = 4.5, y = 6.8; System.out.println(x + y); float cgpa = 3.68f; System.out.println(cgpa); char grade = 'A'; char grade_copy = grade; System.out.println(grade_copy); // Java Constants final float PI = 3.14f; // PI = 3; // Error: Cannot assign a value to final variable 'PI' System.out.println(PI); // Types of Java Variables // - Local Variable (within method or block) // - Instance Variable // - Static Variable } }